Your regex is using lookarounds to capture email address between < and > characters. In your example input it captures email@email.com.

Explanation:

(?<=<) Positive Lookbehind - Assert that the regex below can be matched
< matches the character < literally
.*? matches any character (except newline)
Quantifier: Between zero and unlimited times, as few times as possible,
expanding as needed [lazy]
(?=>) Positive Lookahead - Assert that the regex below can be matched
> matches the character > literally